package com.duma.ld.zhilianlift.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;

public class MyTextView extends android.support.v7.widget.AppCompatTextView {
  
    private int mLineY;  
    private int mViewWidth;  
    public static final String TWO_CHINESE_BLANK = "  ";  
  
    public MyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);  
    }  
  
    @Override  
    protected void onLayout(boolean changed, int left, int top, int right,  
            int bottom) {  
        super.onLayout(changed, left, top, right, bottom);  
    }  
  
    @Override  
    protected void onDraw(Canvas canvas) {
        TextPaint paint = getPaint();
        paint.setColor(getCurrentTextColor());  
        paint.drawableState = getDrawableState();  
        mViewWidth = getMeasuredWidth();  
        String text = getText().toString();  
        mLineY = 0;  
        mLineY += getTextSize();  
        Layout layout = getLayout();
  
        // layout.getLayout()在4.4.3出现NullPointerException  
        if (layout == null) {  
            return;  
        }  
  
        Paint.FontMetrics fm = paint.getFontMetrics();
  
        int textHeight = (int) (Math.ceil(fm.descent - fm.ascent));  
        textHeight = (int) (textHeight * layout.getSpacingMultiplier() + layout  
                .getSpacingAdd());  
        //解决了最后一行文字间距过大的问题  
        for (int i = 0; i < layout.getLineCount(); i++) {  
            int lineStart = layout.getLineStart(i);  
            int lineEnd = layout.getLineEnd(i);  
            float width = StaticLayout.getDesiredWidth(text, lineStart,
                    lineEnd, getPaint());  
            String line = text.substring(lineStart, lineEnd);  
              
            if(i < layout.getLineCount() - 1) {  
                if (needScale(line)) {  
                    drawScaledText(canvas, lineStart, line, width);  
                } else {  
                    canvas.drawText(line, 0, mLineY, paint);  
                }  
            } else {  
                canvas.drawText(line, 0, mLineY, paint);  
            }  
            mLineY += textHeight;  
        }  
    }  
  
    private void drawScaledText(Canvas canvas, int lineStart, String line,  
            float lineWidth) {  
        float x = 0;  
        if (isFirstLineOfParagraph(lineStart, line)) {  
            String blanks = "  ";  
            canvas.drawText(blanks, x, mLineY, getPaint());  
            float bw = StaticLayout.getDesiredWidth(blanks, getPaint());  
            x += bw;  
  
            line = line.substring(3);  
        }  
  
        int gapCount = line.length() - 1;  
        int i = 0;  
        if (line.length() > 2 && line.charAt(0) == 12288  
                && line.charAt(1) == 12288) {  
            String substring = line.substring(0, 2);  
            float cw = StaticLayout.getDesiredWidth(substring, getPaint());  
            canvas.drawText(substring, x, mLineY, getPaint());  
            x += cw;  
            i += 2;  
        }  
  
        float d = (mViewWidth - lineWidth) / gapCount;  
        for (; i < line.length(); i++) {  
            String c = String.valueOf(line.charAt(i));  
            float cw = StaticLayout.getDesiredWidth(c, getPaint());  
            canvas.drawText(c, x, mLineY, getPaint());  
            x += cw + d;  
        }  
    }  
  
    private boolean isFirstLineOfParagraph(int lineStart, String line) {  
        return line.length() > 3 && line.charAt(0) == ' '  
                && line.charAt(1) == ' ';  
    }  
  
    private boolean needScale(String line) {  
        if (line == null || line.length() == 0) {  
            return false;  
        } else {  
            return line.charAt(line.length() - 1) != '\n';  
        }  
    }  
  
}  